Slotted hot top



E. MARBURG SLOTTED HOT TOP Dec. 1, 1959 3 Sheets-Sheet 1 Filed Jan. 24,1957 IN VE/V TOR E 0 6A MARBURG',

his Attorney.

Dec. 1, 1959 E. MARBURG SLOTTED HOT TOP 3 Sheets-Sheet 5 Filed Jan. 24,1957 3/ E 064/? AMA RBURG; B ,4 a y his Attorney.

left of Fi'gure 3;

. Figure is a top plan view 2,914, 25 -S TED ot Top e lt 'farburg, littsb urgh, Pa., assignor to United States Steel Corporation, acorporation of New Jersey Applicationlanuary 24, 1957, Serial No.636,146

' i 12 Claims. c1. 22-147 fThisfinvention relates to a slotted hot topand more particularly to aghottop; for use in casting hot steel ingots.It has been proposed to use slots in hot tops such as suggested byTurner Patents Nos. 2,049,981 and 2,049,-

982 and- Estep PatentNo. 2,159,374. However, the slots shownsthereinextend completely through the hot top so .,thatgi.f the hotmetal flowsinto the slots it is exposed directly to the air. This will cause themetal to chill qrapidly and providemeans for conducting heat directlygramme top of theingot. If the metal does not rise in the slotsthejslotsact as chimneys to convey heat directly from the top of the'ingot. In either case the extraction aofheat from the top of the ingotpromotes undesirable trans-solidification across the ingottop.

referring to the following specification and attached drawings,in'which:

Figure 1 is a plan view. of a sectional hot top assembled on'aningotfmold;

i United States Patent 0 the slab 4 for a purpose which will appearlater. The tops of the end of the slabs 4 are preferably cut away at 18so that they are wider at the bottom than at the top. A generallyvertical groove 20 is provided in the inner face of slab 4 a shortdistance from each end thereof. The bottom of thegroove 20 tapersdownwardly and inwardly at 22 for a purpose which will appear later. Theinner side wall 24 of each groove20 is vertical for the most of itslength, but slopes outwardly in a downward Figure 2is 'anenlarged planview showing the joint bet'ween anend and side slab;

' Figure-3 is anelevation of the side slab looking toward its innerface; a. a t t v 1 "Figure 4 isanend view of the slab looking toward thev of the=slab of FigureS;

Figure 6 is a view, similar to Figure 3, showing the end slab'.

' Figure 7 is an end view of the slab looking toward the left of Figure,6;,

Figure Sis a top plan view of the slab of Figure 6;

Figure 9 is a view in elevation showing the assembled slabs on a-moldsection and looking inwardly from the outer side of an end slab;

Figure 10 is a view of a side slab, similar to Figure 3,

showing a second modification of my invention;

Figure 11 is an end view of the slab looking toward the leftof Figure10;

Figure 12 is a top plan view of the slab of Figure 10;

Figure l3is a view, similar to Figure 6, showing a modified end slabwhich is usedwith the slab of Figures 10 to 12; u

Figure 14 Ban end view of the slab looking toward the leftof Figure 13;and

Figure 15 is a top plan view of the slab of Figure 13.

Referring more particularly to the drawings, reference numeral 2indicates the top of a rectangular big-end-up mold. The hot top consistsof two refractory side slabs 4 and two refractory end slabs 6. The sideslab 4 has a sub- '14. A plurality of holes 16 are provided in the wallof direction at its lower end 25 so that the groove is narrow-v er atthe bottom than at the top. A generally vertical slot 26 is provided inthe upper outer side of slab 4 adjacent each of its ends.

End slab 6 has a generally vertical inner face 28 while its outer facehas a depressed portion 38. The contour of the lower portion of theouter face matches the mold wall. The bottom of the inner face 28 isrounded at 31. Each end ofthe slab 6 has a generally vertical tongue 32which has tapered sides 34. The width of the upper parallel portion oftongue 32 is less than the width of the upper parallel portion of thegroove 20. The lower portion of the tongue 32 has a tapered portion 35which is of the same slope but slightly closer to its basethan taperedportion 22 of slab 4. The inner face of the tongue 32 is tapered at itslower end to provide a wedge surface 32 of the same slope but slightlynearer itsbase than the tapered portion 25 of slab 4. Portion 36 of theend face is normal to the face 28. Portion 38 of the end face slopesinwardly toward the other end face of slab 6. The height of the tongue32 adjacent portion 36 is slightly greater than the depth of groove 20and the height of the opposite side of the tongue 32 is less than thedepth of the groove 20. A generally vertical slot 40 similar to slot 26is provided on the upper outer face of slab Gadjacent each end.

The parts so described except for minor differences are the same asthose shown in my copending application, Serial No. 581,181, filed April27, 1956. My invention in the present application relates to theaddition of a pair of narrow vertical slots 42 in the side slabs 4 andsimilar slots 44in the 'end slabs 6. The width of the slots ispreferably not more than 4 inch. The slots are open at their lower endand'extend upwardly about two thirds the height of the hot top or to anyheight less than that of the hot metal poured into the hot top. I P

To assemble the hot top on the mold 2, a A :inch round steel pin 46 isplaced in corresponding holes 16 (depending on the height of ingotdesired) and the side slabs 4 are placed on opposite sides of the mold 2with the pins 46 resting on top of the mold as best shown in Figure 9.The end slabs 6 are then inserted between the side slabs 4 with thetongues 32 in the grooves 20. Because groove 20 is wider than tongue 32in its parallel upper portion, the tongues 32 will pass readily into thegrooves 20. When the slab 6 reaches the point where bevelled faces 22and 35 are in engagement the outer sides of the side slabs 4 are forcedtowards the mold wall. At the same depth the lower bevels 25 and 32'contact each other, and end slabs 6 are forced outwardly towards themold wall. With clearances allowed, the slight difference in height ofbevelled faces 22 and 35 and corresponding bevels 25 and 32' results inthe tops being aligned when a tight fit is secured. When the top of endpiece 6 is level with the top of side piece 4, the side face 34 oftongue 32 contacts the outer face 24' of groove 20; hence the end slab 6cannot drop below the level of the side slab 4. After the four slabs areassembled, a generally U-shaped spring clip 48 is forced downwardlyacross each joint between the slabs with its legs in the slots 26 and40.

The above manner of assembly is essentially that shown in my copendingpatent application. However, as steel is Patented Dec. 1, 1959' 3 pouredintothe mold it canno-trise intothe narrow slots 42 and 44 because ofthe narrow width of these slots and because the slots are not vented.However, air will be entrapped therein an'd wilhbe heated to a-yery hightemperature,=thusserving as a-neffective'barrierto transverse heat flowfrom the sinkhead throughthe hot top wall.

' i Figures to showa second modification 0f my inventionin which theconstruction and assembly is the same as that of the first embodimentexcept for'the provision of the slots.- Therefore, like referencenumerals *are u'sedto indicate corresponding parts. In thisembodimentwideslots. 50 are 'providedin thetside slabs 4 and "similar"slots 52 are provided inthe-end slabs 6. The -width of the slotsis'preferably at least inch. The slots are open-at their'lower ends andextendupwardly two-thirds the height of the hot top or to anyheightless-=than that-of the metal poured intosthe'hot top. Slotted -vents '54extend from-the top of .the slots 50 to the inner surface of the slab 4.Similar'slotted vents 56 extend from the slots 52 to the inner surfaceof theslab 6. When steel is teemed into the mold it will-rise in theslots50 1 and then inwardly through the slotted ,vents '54 to formsteel'fins which are-connected directly to the sinkhead. Thispreventsthe finsfrom fiaringoutwardly;during rolling. Since the metalfins in the slots 50 and 52 are completely enclosed within the hot topwall the entrapped layer of hot steel will greatly retard heat flowthrough uthe walls of the hot-top and much less heatwill belost --thanin the conventional hot top. It will be understood thatthis arrangementof slots may be incorporated ina "one-piece =hot top as-well as in thesectional hot' top described.

While several embodiments of myinvention have -been shown and describedit will be apparent thatother adaptais relatively wide and there is anopening extending from p the top of the slot to the inner side ofsaid-body-member. '4. A hot top according to claim 1 in which the slotextends upwardly approximately two-thirds the height of the body member.

5.. A sectional-hot top for insertion withinthewalls of a moldcomprising a first pair of refractory slabs supported on said mold inspaced relationship, a second pair of refractory slabs located betweenand in abutting relationship with said first pair of slabs, each end ofboth of the slabs of one of said pair having a generally vertical groovein its abutting faceyand a generally vertical portion adjacent each-endofbothvofi-the slabs of the other of said pair projecting into thecorresponding grooves of the'other slabs, each ofsaidislabs havingaslotextending upwardly-from the bottom of--the-1ab for-afiistanoe less. thanthe full-heightthereof. i

6. A sectional hot top according to claim 5 in which the slot isrelatively narrow and its top closed.

7. A sectional hot top according to claim 5 in which the slot isrelatively wide and there is an opening extending from the top of theslot to the inner side of said slab.

8. A sectional hot top according 'to =claim S in which the slot extendsupwardly approximately two thirds 1 the height of the slab.

9, A sectional hot top 4 for insertion within J the=walls of a' moldcomprising a first pair of refractory slabs supported on said moldin-spaced relationship with-each other, a'second pair-of-refractoryslabs located between and in abutting relationship with-saidfirst pairof slabs, and means on said slabs for wedging them againstithe 'mol'dwall,-each' of said slabs having aslot *extending .upwardly fromwithin'the mold and from the bottomof the slabfor'a distance less thanthe fullheight thereof; 1

10. A- sectional'hot top according-to claim 9 in which the slot isrelatively narrowand itstopclo'sed.

11. A sectional hot top according to clairn-9which the slot isrelativelywide and there is an opening extending from the top of the slot to theinner side of said slab.

12. A sectional hot top according to claim 9 in "which the slot'extendsupwardly approximatelytwo-thirds the height of the slab.

References Cited in' the file of this patent UNITED STATES PATENTS

